When the White Stripes conquered Britain in 2001, in a campaign that took all of a week, the novelty of seeing a two-piece band was countered by scepticism from the chin-strokers. "No bass player?" they mused. "How will that work if they play longer sets and bigger stages?" Countless headline festival slots answered that question, but Jack and his "little sister" Meg were still considered unique; the Musicians Union wouldn't have foreseen what happened next. While the myth of four guys who shook the world has served us well from the Beatles to the Roses, in 2012, two-piece bands are now the industry-standard shape of cool rock.

Recessionary factors are undoubtedly at play: for the acts, it's cheaper and easier to pack the gear, travel, get gigs and make ends meet; for the labels, two egos are easier to deal with than four, and often more artistically simpatico. The recent success of Sleigh Bells, Beach House, Crystal Castles and Summer Camp has shown that a partnership can produce a more tightly focused project.

All those acts, like the Kills before them, are happy to embellish their live sound with loops, synths and samples, but those two-pieces who make a virtue of their restricted means are arguably more interesting. Trailblazers in this respect were Death From Above 1979, who didn't let their minimalist drums'n'bass set-up stop them from going full-on disco-punk. Brighton's Blood Red Shoes, too, manage to channel every early-90s US college rock band, despite the absence of a bassist, second guitarist and plaid shirts. Here to save us from the Mumfords/Marling axis of niceness are doughty folk-grunge pairing Two Gallants; while in the not-entirely-crowded field of post-Black Keys blues-rock duos you might want to listen to, the Hot Soles deserve kudos for sounding like Solomon Burke fronting a 60s power trio (without the bassist, naturally).

This year has seen an unexpected Black Keys-style breakthrough for Vancouver's Japandroids, who've blossomed from a noise-rock duo into blue-collar anthemicists, acclaimed by the NY Times as having "by far the most exuberant, affirming live show" of any two-piece they've seen (that's including the White Stripes). The US public agrees: the band's Celebration Rock album went top 40.

In February, a Philadelphia festival dedicated solely to two-pieces showcased no less than 40, from turbo thrashers +HIRS+ (who've just released a 100-track album) to intense feminist punks Trophy Wife (not to be confused with the Oxford band of the same name who have three members, the hippies). "I thought it'd be cool to see what two-pieces were out there," Two Piece Fest organiser Craig Woods told the Philadelphia Weekly. "Apparently there's a shit ton."

There's undoubtedly purity in a pairing: you can't contemplate the White Stripes re-forming without Meg; it would be every bit as forlorn as when one London boozer listed a knees-up in the Guide featuring "Chas & Dave (not original Dave)". With Two Piece Fest inspiring a copycat event in Wellington, New Zealand this year – headlined by Aussie thrash-pop scamps DZ Deathrays – and festivals having a tough time of it, will UK promoters be next to see the benefit of binary bands? They could save 50% on riders alone.